PIC18F8520-I/PT - 8-Bit 40MHz MCU 32KB Flash 80-TQFP | Microchip
MPN: PIC18F8520-I/PT ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $8.95 | $8.95 |
| 10 | $7.92 | $79.20 |
| 100 | $6.88 | $688.00 |
| 500 | $5.94 | $2,970.00 |
| 1,000 | $5.1586 | $5,158.60 |
PIC18F8520-I/PT Overview
A microcontroller (MCU) is a single-chip computer that integrates a CPU core, program and data memory, peripherals, and I/O on one die. The PIC18 family uses an enhanced 8-bit RISC architecture with a 16-bit instruction word; PIC18F8520-I/PT fits in the broader taxonomy of 8-bit MCU -> PIC -> PIC18F85xx -> 80-pin high-pin-count devices, positioned between smaller 64-pin PIC18F65xx parts and larger PIC18F87xx/88xx family members.
Key features of PIC18F8520-I/PT include 70 I/O pins, an internal 10-bit ADC of up to 16 channels, two USART modules, an MSSP (I2C/SPI) port, two CCP modules, one Enhanced CCP (ECCP), two 8-bit and three 16-bit timers, two analog comparators, an internal programmable LDO, and a 4x phase-locked-loop (PLL) for clock multiplication. The Flash memory supports self-programming and 100k erase/write cycles, while the data EEPROM supports 1M cycles typical. Code protection, BOR, LVD, and WDT are included for safety-critical firmware.
Architecturally, the device pairs a 2-stage pipeline Harvard core with a 10-bit ADC fed by an analog input mux and optional internal bandgap reference; the PLL supports 4x/8x scaling relative to the primary oscillator. Operating voltage spans 4.2V to 5.5V (industrial), with an extended 2.0V-5.5V variant available in the same family. The 80-TQFP package offers 70 usable I/O with multiple peripheral remapping options, enabling designers to dedicate pins for parallel master port, external memory interface, or analog-heavy front-ends.
Typical applications include industrial control panels, HVAC thermostats, white-goods motor control, USB/serial human-machine interfaces, instrumentation front-ends, and automotive body/lighting controllers (using the PIC18F8520-I/PT or the AEC-Q100 automotive-grade -I/PT variant). The dual USART plus MSSP make it a natural fit for bridging RS-232/RS-485 to SPI/I2C peripherals such as sensors or external memory.
When designing with this MCU, place a 100 nF decoupling capacitor close to each VDD/VSS pair and tie the MCLR pin through the recommended 10 kohm pull-up; a 10 kohm pull-down is recommended on RA5 if the device is used in applications where parasitic current draw is unacceptable during reset. The PLL configuration bits must be set before enabling the PLL output, otherwise the MCU will not leave reset.
Drop-in alternatives for PIC18F8520-I/PT — same package, pin-to-pin compatible. Different-package parts requiring PCB rework are excluded.
Variants in this series
Same-series models that are drop-in compatible with PIC18F8520-I/PT (same form factor and footprint) — differing in Package, Core Architecture, Operating Temperature, Timers, ADC.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
PIC18F8520T-I/PT
✅ Drop-In📋 Reference alternative (not in catalog)
PIC18F8520-E/PT
✅ Drop-In📋 Reference alternative (not in catalog)
PIC18F8620-I/PT
✅ Drop-In ⚠️ Specs Unverified📋 Reference alternative (not in catalog)
PIC18F67K90-I/PT
✅ Drop-In✓ In Stock
$7.55 / Unit
View Datasheet →PIC18F8520T-I/PTG
✅ Drop-In📋 Reference alternative (not in catalog)
PIC18F6720-I/PT
✅ Drop-In ⚠️ Specs Unverified✓ In Stock
$21.1 / Unit
View Datasheet →PIC18F8520-I/PT Maximum Ratings & Electrical Characteristics
| Core Architecture | 8-bit PIC18 enhanced RISC |
| Family | PIC18F85xx |
| Instruction Width | 16-bit |
| Maximum Clock Speed | 40 MHz |
| Program Memory (Flash) | 32 KB (16K x 16) |
| RAM | 2048 bytes |
| EEPROM | 1024 bytes |
| Supply Voltage | 4.2 V to 5.5 V |
| I/O Pins | 70 |
| Package | 80-pin TQFP (12 x 12 mm, 1 mm height) |
| Mounting Type | Surface Mount |
| ADC | 10-bit, up to 16 channels |
| Serial Interfaces | 2x USART, 1x MSSP (I2C/SPI), 1x CAN (per family datasheet) |
| Timers | 2x 8-bit, 3x 16-bit |
| CCP / ECCP Modules | 2x CCP + 1x ECCP |
| Comparators | 2x analog comparators |
| Operating Temperature Range | -40 C to +85 C (industrial, -I suffix) |
| RoHS Status | Compliant |
| MSL Level | 3 (168 hours) |
| Lead Free | Yes |
PIC18F8520-I/PT Pin Configuration
| Pin 1 | RG0 — Digital I/O / Parallel Master Port data |
| Pin 2 | RG1 — Digital I/O / Parallel Master Port data |
| Pin 3 | RG2 — Digital I/O / Parallel Master Port data |
| Pin 4 | RG3 — Digital I/O / Parallel Master Port data |
| Pin 5 | RG4 — Digital I/O / Parallel Master Port data |
| Pin 6 | MCLR — Master Clear reset (active low) |
| Pin 7 | RA0/AN0 — Digital I/O / ADC input 0 |
| Pin 8 | RA1/AN1 — Digital I/O / ADC input 1 |
| Pin 9 | RA2/AN2 — Digital I/O / ADC input 2 |
| Pin 10 | RA3/AN3 — Digital I/O / ADC input 3 |
| Pin 11 | RA4/T0CKI — Digital I/O / Timer0 clock input |
| Pin 12 | RA5/AN4 — Digital I/O / ADC input 4 |
| Pin 13 | VSS — Ground |
| Pin 14 | RA6/OSC2 — Digital I/O / oscillator output |
| Pin 15 | RA7/OSC1 — Digital I/O / oscillator input |
| Pin 16 | RB0/INT0 — Digital I/O / External interrupt 0 |
| Pin 17 | RB1/INT1 — Digital I/O / External interrupt 1 |
| Pin 18 | RB2/INT2 — Digital I/O / External interrupt 2 |
| Pin 19 | RB3/INT3 — Digital I/O / External interrupt 3 |
| Pin 20 | RB4 — Digital I/O / interrupt-on-change |
| Pin 21 | RB5 — Digital I/O / interrupt-on-change |
| Pin 22 | RB6/PGC — Digital I/O / ICSP clock |
| Pin 23 | RB7/PGD — Digital I/O / ICSP data |
| Pin 24 | RC0/T1OSO — Digital I/O / Timer1 oscillator output |
| Pin 25 | RC1/T1OSI — Digital I/O / Timer1 oscillator input |
| Pin 26 | RC2/CCP1 — Digital I/O / CCP1 output |
| Pin 27 | RC3/SCK/SCL — Digital I/O / SPI clock / I2C clock |
| Pin 28 | RC4/SDI/SDA — Digital I/O / SPI data in / I2C data |
| Pin 29 | RC5/SDO — Digital I/O / SPI data out |
| Pin 30 | RC6/TX1/CK1 — Digital I/O / USART1 TX or clock |
| Pin 31 | RC7/RX1/DT1 — Digital I/O / USART1 RX or data |
| Pin 32 | VDD — Positive supply (4.2-5.5 V) |
| Pin 33 | VSS — Ground |
| Pin 34 | RD0/PSP0 — Digital I/O / Parallel Slave Port data |
| Pin 35 | RD1/PSP1 — Digital I/O / Parallel Slave Port data |
| Pin 36 | RD2/PSP2 — Digital I/O / Parallel Slave Port data |
| Pin 37 | RD3/PSP3 — Digital I/O / Parallel Slave Port data |
| Pin 38 | RD4/PSP4 — Digital I/O / Parallel Slave Port data |
| Pin 39 | RD5/PSP5 — Digital I/O / Parallel Slave Port data |
| Pin 40 | RD6/PSP6 — Digital I/O / Parallel Slave Port data |
| Pin 41 | RD7/PSP7 — Digital I/O / Parallel Slave Port data |
| Pin 42 | RE0/RD — Digital I/O / Parallel Slave Port read strobe |
| Pin 43 | RE1/WR — Digital I/O / Parallel Slave Port write strobe |
| Pin 44 | RE2/CS — Digital I/O / Parallel Slave Port chip select |
| Pin 45 | AVSS — Analog ground |
| Pin 46 | AVDD — Analog positive supply |
| Pin 47 | RF0/AN5 — Digital I/O / ADC input 5 |
| Pin 48 | RF1/AN6 — Digital I/O / ADC input 6 |
| Pin 49 | RF2/AN7 — Digital I/O / ADC input 7 |
| Pin 50 | RF3/AN8 — Digital I/O / ADC input 8 |
| Pin 51 | RF4/AN9 — Digital I/O / ADC input 9 |
| Pin 52 | RF5/AN10/CVREF — Digital I/O / ADC input 10 / CVREF out |
| Pin 53 | RF6/AN11 — Digital I/O / ADC input 11 |
| Pin 54 | RF7/AN12 — Digital I/O / ADC input 12 |
| Pin 55 | RG5 — Digital I/O / Parallel Master Port data |
| Pin 56 | RH0/A16 — Digital I/O / External memory address 16 |
| Pin 57 | RH1/A17 — Digital I/O / External memory address 17 |
| Pin 58 | RH2/A18 — Digital I/O / External memory address 18 |
| Pin 59 | RH3/A19 — Digital I/O / External memory address 19 |
| Pin 60 | RH4/AN13 — Digital I/O / ADC input 13 |
| Pin 61 | RH5/AN14/C2OUT — Digital I/O / ADC input 14 / Comparator 2 out |
| Pin 62 | RH6/AN15 — Digital I/O / ADC input 15 |
| Pin 63 | RH7 — Digital I/O |
| Pin 64 | RJ0 — Digital I/O |
| Pin 65 | RJ1 — Digital I/O |
| Pin 66 | RJ2 — Digital I/O |
| Pin 67 | RJ3 — Digital I/O |
| Pin 68 | RJ4 — Digital I/O |
| Pin 69 | RJ5 — Digital I/O |
| Pin 70 | RJ6 — Digital I/O |
| Pin 71 | RJ7 — Digital I/O |
| Pin 72 | RK0 — Digital I/O |
| Pin 73 | RK1 — Digital I/O |
| Pin 74 | RK2 — Digital I/O |
| Pin 75 | RK3 — Digital I/O |
| Pin 76 | RK4 — Digital I/O |
| Pin 77 | RK5 — Digital I/O |
| Pin 78 | RK6 — Digital I/O |
| Pin 79 | RK7 — Digital I/O |
| Pin 80 | VDD — Positive supply (4.2-5.5 V) |
Typical Applications
PIC18F8520-I/PT is suitable for 6 applications: Industrial Control Panels, HVAC Thermostats and Climate Controllers, White Goods and Appliance Motor Control, Instrumentation Front-Ends, Serial-Protocol Bridges and Gateways, Automotive Body and Lighting Modules.
Industrial Control Panels
The PIC18F8520-I/PT is well suited for industrial control panels requiring up to 70 I/O pins to drive relays, keypads, LEDs, and 4-20 mA sensor loops. The 40 MHz core runs 10 MIPS, supporting Modbus RTU over RS-485 via the dual USART, while the ECCP module generates PWM for proportional valve or actuator control. The 10-bit ADC with 16 channels reads thermocouples, pressure transducers, and 0-10 V analog inputs. The 32 KB Flash and 1 KB EEPROM comfortably host Modbus stacks, PID loops, and configuration storage. The 80-pin TQFP allows PCB layout reuse across product variants. Compared to discrete PLC designs, this MCU reduces component count by ~60%.
Recommended
HVAC Thermostats and Climate Controllers
HVAC thermostats benefit from the PIC18F8520-I/PT's dual USART for Modbus or BACnet MS/TP comms to a building management system, the 10-bit ADC for NTC thermistor and humidity sensor reads, and the ECCP module for PWM control of variable-speed blower fans. The 1 KB EEPROM stores calibration constants and user setpoints across 1M write cycles, supporting decades of program updates. The -40 C to +85 C industrial temperature rating covers unconditioned mechanical rooms and rooftop enclosures. Compared to a discrete 8051 design, the PIC18F8520-I/PT integrates the brown-out reset, watchdog timer, and oscillator on-chip, reducing BOM by ~40%.
Recommended
White Goods and Appliance Motor Control
Washing machines, dishwashers, and induction cooktops use the PIC18F8520-I/PT's ECCP module to generate complementary PWM for driving three-phase IGBT inverters up to 20 kHz. The 70 I/O handle user-panel buttons, 7-segment LED drives, water-level sensors, and door interlocks. The MSSP port interfaces to SPI-based motor position encoders (e.g., AS5048A) for closed-loop commutation. The 32 KB Flash runs FOC (field-oriented control) firmware and the 2 KB RAM stores per-cycle variables. Compared to PIC18F452-based designs, the 8520-I/PT adds a second USART for diagnostic log output and more CCP channels for multi-motor appliances.
Recommended
Instrumentation Front-Ends
Laboratory and field instrumentation uses the PIC18F8520-I/PT for its 16-channel 10-bit ADC, dual USART for RS-232/RS-485 instrument buses, and ample Flash/RAM for data logging. The 40 MHz core samples multi-channel waveforms and applies digital filtering in real time. The 80-TQFP package exposes the parallel master port for direct interfacing to external SRAM or color TFT LCDs without address-latch glue logic. Compared to ARM Cortex-M0 designs, the PIC18 platform offers deterministic interrupt latency and 16-bit instruction set, easing assembly-language optimization for signal-processing routines.
Recommended
Serial-Protocol Bridges and Gateways
The PIC18F8520-I/PT is ideal for protocol-conversion gateways between RS-232, RS-485, CAN, I2C, and SPI, leveraging its dual USART plus MSSP in a single chip. The 32 KB Flash hosts Modbus, BACnet, and CANopen stacks; the 2 KB RAM buffers incoming telegrams. The 70 I/O provide status LEDs, push-buttons, and config DIP switches. Compared to dedicated protocol converters, the 8520-I/PT is firmware-configurable across protocols. Designers reuse the same hardware across product SKUs by changing firmware, cutting time-to-market for industrial automation product lines.
Recommended
Automotive Body and Lighting Modules
Although the PIC18F8520-I/PT itself is industrial-grade (not AEC-Q100), its 80-TQFP pinout and peripheral map form the basis for automotive body and lighting control firmware. For automotive applications, designers choose the PIC18F8520-I/PT -Q1 or PIC18F67K90-I/PT variants which carry AEC-Q100 qualification. The ECCP module drives LED dimmers and turn-signal PWMs; the dual USART handles LIN bus and CAN interfacing. The 32 KB Flash runs bootloader and LIN slave stacks. Compared to automotive ASICs, this MCU reduces qualification cost for low-volume specialty vehicle programs.
Recommended
Recommended Products Summary
Engineering reference data for PIC18F8520-I/PT — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC18F8520T-I/PT | PIC18F8520-E/PT | PIC18F8620-I/PT | PIC18F67K90-I/PT | PIC18F6720-I/PT |
|---|---|---|---|---|---|---|
| Package | 80-pin TQFP (12x12 mm) | 80-pin TQFP (12x12 mm) - same | 80-pin TQFP (12x12 mm) - same | 80-pin TQFP (12x12 mm) - same | 80-pin TQFP - same | 80-pin TQFP - same |
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Core | 8-bit PIC18 RISC, 40 MHz | 8-bit PIC18 RISC, 40 MHz - same | 8-bit PIC18 RISC, 40 MHz - same | 8-bit PIC18 RISC, 40 MHz - same | 8-bit PIC18 enhanced, 64 MHz - higher | 8-bit PIC18 RISC, 25 MHz - lower |
| Flash Memory | 32 KB | 32 KB - same | 32 KB - same | 64 KB (+100%) | 128 KB (+300%) | 32 KB - same |
| RAM | 2 KB | 2 KB - same | 2 KB - same | 4 KB (+100%) | 4 KB (+100%) | 2 KB - same |
| EEPROM | 1 KB | 1 KB - same | 1 KB - same | 1 KB - same | 1 KB - same | 1 KB - same |
| I/O Pins | 70 | 70 - same | 70 - same | 70 - same | 69 (-1) | 52 (-18) |
| Operating Voltage | 4.2 V to 5.5 V | 4.2 V to 5.5 V - same | 4.2 V to 5.5 V - same | 4.2 V to 5.5 V - same | 1.8 V to 5.5 V - wider | 4.2 V to 5.5 V - same |
| Operating Temperature | -40 C to +85 C (industrial) | -40 C to +85 C - same | -40 C to +125 C - extended | -40 C to +85 C - same | -40 C to +85 C - same | -40 C to +85 C - same |
| Unit Price (qty-1000, USD) | 5.16 | 5.16 - same | 5.95 - +15% | 6.20 - +20% | 7.40 - +43% | 4.95 - -4% |
Key Differentiators
- 70 I/O pins in 80-pin TQFP - highest pin count in PIC18F85xx subfamily (vs PIC18F6720-I/PT)
- Extensive peripheral set with dual USART, ECCP, MSSP, and 16-channel ADC (vs PIC18F4585-I/PT (40-pin PIC18F4585))
- Software-compatible upgrade path to 64 KB Flash / 4 KB RAM (vs PIC18F8520T-I/PT)
Design Notes
Place a 100 nF ceramic decoupling capacitor within 5 mm of every VDD/VSS pair; the 80-TQFP has multiple VDD pins (typically pins 32 and 80) and each should be independently decoupled. Add a 10 uF bulk capacitor near the MCU for transient load response during ADC conversions and USART bursts. For analog reference stability, separate AVDD/AVSS from digital VDD/VSS using a ferrite bead, as recommended in Microchip application note AN230.
Estimated: at 40 MHz core clock, 5.0 V supply, all 70 I/O toggling at 1 MHz, the PIC18F8520-I/PT dissipates roughly 250 mW. The 80-TQFP thermal resistance (theta_JA) is approximately 45 C/W on a 4-layer JEDEC test board, giving a 11 C rise above ambient. For industrial -40 C to +85 C operation, no heatsink is required; for automotive under-hood designs choose the PIC18F8520-E/PT (125 C) variant.
Route the crystal oscillator traces (OSC1/OSC2 or RA6/RA7) as short as possible with grounded guard traces; keep them away from high-speed switching signals such as PWM or USART lines. Place the MCLR pull-up resistor (typically 10 kohm) within 5 mm of the pin, and add a 100 nF cap if MCLR noise immunity is needed. Maintain a continuous ground plane under the MCU for thermal spreading and EMI suppression. For 80-pin TQFP land pattern, follow IPC-7351 nominal land dimensions (0.5 mm pitch).
Do not enable the 4x PLL before configuring the primary oscillator mode bits (OSCCON and CONFIG1H); the device will reset indefinitely if PLL is enabled with an unsupported clock source. Avoid using RA4 as an output without the internal weak pull-up enabled, since RA4 is open-drain. When using ICSP, do not load capacitor values above 1 nF on PGC/PGD, as this prevents reliable programming. Always set the configuration bits (CONFIG1L through CONFIG5H) before code development to match the application.
For SPI clock speeds above 5 MHz, add a 33 ohm series resistor at SCK to dampen ringing on long PCB traces (>50 mm). For I2C buses above 400 kHz, use 4.7 kohm pull-ups instead of 10 kohm, and verify rise-time against the bus capacitance budget. When using the ADC in 16-channel scan mode, add a 100 nF cap on each analog input if the source impedance exceeds 2.5 kohm, as recommended in the PIC18F8520 datasheet ADC section.
Compliance Information
Per Microchip product page, the PIC18F8520-I/PT is RoHS-compliant and lead-free. Not AEC-Q100 qualified - choose automotive-grade variants (with -Q1 suffix) for vehicle applications. Halogen-free per Microchip material declaration.
